This invention relates generally to medical imaging systems and, more particularly, to automatically matching lesions in medical images acquired by a medical imaging system at different times.
Positron emission tomography (PET) generally involves acquiring images showing physiologic data based on the detection of radiation from the emission of photons. Images acquired using PET may be used to evaluate different conditions and diseases, for example, to detect cancer and evaluate the progression or regression of the cancer. Other examinations using PET include, for example, heart scans or brain scans.
PET scans are increasingly being used in connection with other types of medical scans, including, for example, with computed tomography (CT) scans and/or magnetic resonance imaging (MRI) scans. The combination of the images from the scans, often referred to as co-registration, provides both anatomic and metabolic information on a single image. Combination or multimodality scanners are also available to perform both scans during the same scanning session.
However, registration is an issue when performing a first examination, such as a baseline examination, and a subsequent examination at a later time. For example, reading PET examinations and examining tumor response between a baseline image and a follow-up image is a very time consuming process that often results in reduced patient examination throughput. In particular, when evaluating the baseline image and comparing to the follow-up image, one of the slow and tedious steps is finding the lesions on the follow-up image previously identified on the baseline image and matching corresponding lesions from the two images. This process not only adds time and cost to overall examination, but can result in errors and potential improper diagnosis of the lesions that are not properly identified and matched in the images.